One thing we can be certain of is that the Ogham alphabet is, and it seems it always was, closely linked with several trees in some way.

I first learned a version of "Ogma's Tale Of The Trees" was while working on Iona around 1973.

The tale I tell today is of different words to the tale I first told 35 years ago, but the meanings, the connections, the unseen learning and wisdom between the words has never changed.

The grounding of my tale considers the original Ogham as 20 symbols,
4 octaves of 5 symbols each (pentatonic)
and each symbol sharing a mythology of a tree, shrub or climber to reveal its symbol.

The 4 original octaves, I feel, pass like the seasons of a year, the four seasons of our lives, and the cycle of the four quadrants in an astrology chart

First Octave travels through the gauntlet of discovering who we are
Second Octave, our discovery of what and who we connect with
Third Octave, our journey of creativity and unity with others
Fourth Octave, defines our service